[Not Applicable ]
1. Field of the Invention
The present invention relates to a golf club striking plate. More specifically, the present invention relates to a golf ball striking plate having a variable bulge and roll.
2. Description of the Related Art
In order to reduce hooking and slicing of a golf ball, golf club manufacturers have constructed clubs that have faces with convex curvatures of radius along a horizontal plane (the bulge) and convex curvatures of radius along a vertical plane (the roll). The bulge radius reduces the tendency to hook and slice while the roll radius lowers the spin to increase the distance lost to the bulge radius. Typically, the face has had only one bulge radius of curvature and a single roll radius of curvature.
Presently, high performance, large volume golf club heads (in excess of 300 cubic centimeters in volume) having deeper or more circular faces have been introduced by golf club manufacturers. The high performance, large volume golf club heads generally provide greater distance off the tee for a typical golfer. However, the large surface area of the faces has led to more off-center shots that hook or slice further than previous golf clubs. Thus, current high performance, large volume golf club heads provide for greater distance but are less forgiving than previous golf club heads such as the BIGGEST BIG BERTHA(copyright) from the Callaway Golf Company of Carlsbad, Calif.
Many persimmon woods rounded off the upper toe quadrant and lower heel quadrant of the face of the golf club head in order to improve the appearance of the golf club head. This rounding off effected the bulge radius of curvature and roll radius of curvature in such areas of the face. An example of such is the CALLAWAY(copyright) CLASSIC SERIES, which was sold in the eighties by the Callaway Golf Company.
Vincent, U.S. Pat. No. 5,415,405, filed originally in France in 1992, for a Hitting Surface Of A Golf Club Head, discloses a face that has at least three bulge radii of curvature along an imaginary line with adjacent bulge radii having unequal radii.
Japanese Laid-Open Patent Application Number 05177018, filed in 1991 for a Golf Club Head, discloses a protruded curved surface of the face that has a larger curvature than the curvature at the center of the face.
Kinney, III, U.S. Pat. No. 4,725,062, filed in 1986, for a Wood-Type Golf Club Head, discloses a golf club head with a rounded face having a single vertical roll and a single horizontal bulge.
European Patent Application Number 1005882, originally filed in the U.S. in 1998 as Ser. No. 203563, discloses a golf club head with a face that has at least two bulge radii of curvature.
Schmidt, U.S. Pat. No. 4,367,878, filed in 1981, for a Golf Club Head, discloses a golf club head with a parabolic face.
Solheim, U.S. Pat. No. 3,625,518, for a Golf Club Head With Complex Curvature For The Sole And/Or The Striking Face, filed in 1969, discloses a wood golf club head that has a complex bulge curvature and complex roll curvature in relation to an elliptical sweet spot area of the striking face.
Mikame et al., U.S. Pat. No. 5,681,228, for a Golf Club Head, filed in 1995, discloses a golf club head that has a single bulge curvature and a single roll curvature that are both in relation to a gravity depth of the golf club head.
Gebauer et al., U.S. Pat. No. 4,508,349, for a Golf Club, filed in 1983, discloses a golf club head that has a bulge radius of curvature that increases toward the heel of the club head and decreases toward the toe of the club head.
Although the prior art has disclosed golf club head with faces that have variable bulge and roll curvatures, the prior art has failed to address specific variation of the bulge and roll curvatures for large size, high volume golf club heads.
The present invention is directed at a striking plate for a high performance, large volume golf club head that has a variable roll radius of curvature and a variable bulge radius of curvature to correct off-center shots. Further, the striking plate has regions of varying thickness that allow for more compliance during impact with a golf ball.
One aspect of the present invention is a golf club head having a body having a crown, a sole, a heel end, a toe end and a striking plate. The striking plate has a first roll radius along a vertical mid-area and a second roll radius along an upper toe quadrant or a lower heel quadrant. The striking plate may also have a roll radius of curvature in the other of the upper toe quadrant or the lower heel quadrant.
Another aspect of the present invention is a golf club head including a body having a crown, a sole, a heel end and a toe end, and a striking plate. The striking plate has a first bulge radius along a vertical mid-area and a second bulge radius along an upper toe quadrant or a lower heel quadrant. The striking plate may also have a third bulge radius along the other of the upper toe quadrant or the lower heel quadrant of the striking plate.
Yet another aspect of the present invention is a striking plate for a golf club head. The striking plate includes a first roll radius along a vertical mid-area of the striking plate, a second roll radius along an upper toe quadrant of the striking plate, a third roll radius along a lower heel quadrant of the striking plate, a first bulge radius along a horizontal mid-area of the striking plate, a second bulge radius along an upper toe quadrant of the striking plate, and a third bulge radius along a lower heel quadrant of the striking plate.
The primary object of the present invention is to provide a striking plate for a golf club head that has a variable bulge radius of curvature and/or a variable roll radius of curvature.
Having briefly described the present invention, the above and further objects, features and advantages thereof will be recognized by those skilled in the pertinent art from the following detailed description of the invention when taken in conjunction with the accompanying drawings.